First Data on Testate Amoeba Composition in Tropical Karst Wetlands of Northern Vietnam in Relation to Type of Biotope and Season: New Bioindication Potentialities

2020 ◽  
Vol 13 (2) ◽  
pp. 251-261
Author(s):  
Hoan Q. Tran
2020 ◽  
Vol 10 (3) ◽  
pp. 858 ◽  
Author(s):  
Zhang Liankai ◽  
Ji Hongbing ◽  
Wang Shijie ◽  
Luo Gang ◽  
Liu Xiuming ◽  
...  

Research on weathered crusts on carbonate rock is essential for paleoenvironmental studies in karst areas. Terra rossa, widely distributed in tropical karst areas, has not been studied in terms of its material sources and geochemistry. Two typical terra rossa profiles on dolomite (SC profile located at Sang Cai, Hoa Binh province) and limestone (TG profile located at Tong Gia, Lao Cai province) in Northern Vietnam were selected to examine the geochemical characteristics and the evolutionary processes of rare earth elements (REEs). Chondrite and bedrock normalized patterns indicated that these two profiles are in situ weathering crusts, meaning they are the residual material remaining after chemical weathering of the lower carbonate rocks. The average value of total REE in the SC profile is 381.19 ppm, which is 30 times higher than the bedrock. In the TG profile, the value is 386.26 ppm, 13 times higher than the bedrock. Compared with the profiles in nearby subtropical areas in Southeast China, the REE enrichment coefficients of terra rossa in Northern Vietnam are much higher. The REE depletion was also different between the SC and TG profiles. The light and heavy REE fractionations in the SC profile are higher than in the TG profile. Paleoclimate inversion analysis shows that the SC profile experienced a stable oxidation condition, whereas the TG profile was subjected to several reducing environments since a weathering crust formed.


2019 ◽  
Vol 26 (6) ◽  
pp. 325-334
Author(s):  
Ivan I. Kropachev ◽  
Nikolai L. Orlov ◽  
Hoa Thi Ninh ◽  
Tao Thien Nguyen

We describe a new species of the Rhacophorus genus, which differs from all species known in Asia by the combination of characters. It strongly differs also from small and middle-sized species of Rhacophorus sensu lato: Rhacophorus calcaneus Smith, 1924, Leptomantis cyanopunctatus (Manthey et Steiof, 1998), Rhacophorus hoabinhensis Nguyen, Pham, Nguyen, Ninh et Ziegler, 2017, Rhacophorus hoanglienensis Orlov, Lathrop, Murphy et Ho, 2001, Zhangixalus jarujini (Matsui et Panha, 2006), Rhacophorus laoshan Mo, Jiang, Xie et Ohler, 2008, Rhacophorus pardalis Günther, 1858, Rhacophorus rhodopus Liu et Hu, 1960, Rhacophorus robertingeri Orlov, Poyarkov, Vassilieva, Ananjeva, Nguyen, Sang, and Geissler, 2012, Leptomantis robinsonii (Boulenger, 1903), Rhacophorus spelaeus Orlov, Gnophanxay, Phimminith, and Phomphoumy, 2010, Rhacophorus translineatus Wu, 1977, Rhacophorus turpes Smith, 1940, Rhacophorus vampyrus Rowley, Le, Thi, Stuart et Hoang, 2010, Rhacophorus viridimaculatus Ostroshabov, Orlov et Nguyen, 2013 by having brown color with two green dorsolateral stripes starting at the groin level and connecting through the distal part of eyelid with green triangle on the head, slender body and head, lower ratio HW/HL 0.86, lower HW/SVL 0.28 and lower ratio HL/SVL 0.32.


2010 ◽  
Vol 19 (1) ◽  
pp. 29-34
Author(s):  
A.V. Gorochov

Prohimerta (Anisotima) laocai sp. nov. from Northern Vietnam and Paraducetia cruciata gialai subsp. nov. from Central Vietnam are described. Corrected are some erroneous data on systematic position of Prohimerta (Anisotima) vieta, P. (Prohimerta) maculosa, and Paraducetia cruciata, as well as those on the type locality of P. maculosa.


2010 ◽  
Vol 5 (3) ◽  
Author(s):  
H. Harada ◽  
N. T. Dong ◽  
S. Matsui ◽  
S. Fujii

Northern Vietnam has a history of using urine diversion (i.e., UD) toilets with agricultural use of excreta. This study tried to identify the current practices of UD toilets in suburban Hanoi, Vietnam. An interview survey to 120 households showed that UD toilets were used by 26.7% of households, of which most were double-vault UD toilets. Human wastes were used by 73.0% of vault toilets. It was interpreted that they are still recognized as not wastes but fertilizers especially by farming households in recent sub-urban Hanoi. Double-vaults UD toilets were used in significantly old houses compared to flush toilets with p<0.001. Results indicated the gradual replacement of double-vault UD toilets by water-flush toilets. All households with vault toilets applied additives such as ashes, dry soil and sawdust into vaults, and 24.3% of them applied ashes after every defecation event. Out of 33 vault toilets, 30 retained faeces for a period longer than six months and 28 did for a period longer than 12 months. Still, the application of ashes after every defecation event can be suggested to enhance the disinfection process in vaults, resulting sanitary use of excreta for agriculture.


2007 ◽  
Vol 96 (1-2) ◽  
pp. 219-233 ◽  
Author(s):  
Alan D. Ziegler ◽  
Thomas W. Giambelluca ◽  
Ross A. Sutherland ◽  
Mike A. Nullet ◽  
Tran Duc Vien

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